Ankylosing spondylitis (AS) is the prototype disease within the spondyloarthropathies (SpA), a group of diseases presenting mainly with spondylitis, pauci-articular peripheral arthritis and enthesiopathy. Non-steroidal anti-inflammatory drugs (NSAID) are the classical cornerstone of medical therapy in these patients; no real disease modifying antirheumatic treatment was available, until recently. TNF-alpha blocking agents (monoclonal antibodies or soluble receptors) are the first representative drugs, of which the indication has recently been expanded to encompass also patients with AS. Here, we review the data on clinical efficacy and safety, with focus on the compounds infliximab and etanercept. Publication of trial results with adalimumab is still under way; the efficacy of this compound in AS seems comparable with the other two agents.